The present invention relates generally to a conveying auger for agricultural combines. In particular, the present invention relates to a bubble up auger having an improved inlet opening for improving efficiency in the amount of grain transported through the auger.
Mechanical harvesting of grain has taken place for decades. However, efforts continue in the attempt to make harvesting operations more efficient and effective. A combine harvester generally includes a header which cuts the crop. The header then moves the cut crop into a feeder house. The feeder house lifts the cut crop into the threshing, separation and cleaning areas of the agricultural combine. The grain is separated from crop stalk by a rotor or threshing system. The grain is then cleaned, transported, and stored in a grain tank. The chaff and trash are deposited from the rear of the agricultural combine. The grain stored in the grain tank is eventually discharged through a grain tank unloader tube. An operator usually runs these various operations from a glass-enclosed cab.
Grain processed through the threshing and separating system then enters a clean grain elevator typically positioned on one side of the combine. The elevator is an endless chain elevator with a series of lift arms attached to the chain. The arms lift the grain upwards. Near the top of the elevator the grain is deposited to a base of a bubble up auger. The bubble up auger moves the grain towards the center of the grain tank. At the end of the bubble up auger the grain is discharged into the grain tank's center. Conventional bubble up augers are hinged near the base of the auger so that the auger can rotate or pivot to a transport, or substantially horizontal position. To discharge the grain from the grain tank, there is an auger, or augers positioned at the bottom of the grain tank. This grain tank auger moves grain to a grain tank unloading auger. The grain tank unloading auger is extended away from the grain tank and discharges the grain into a nearby transport vehicle.
Conventional bubble up augers, however, have a relatively small inlet opening formed by the walls of a tubular housing of the auger. Furthermore, given the auger inclination angle when the bubble up auger is in a harvest or inclined position, significant void space within the auger results and thereby reduces conveying efficiency compared to an auger operating in a transport or substantially horizontal position. Therefore, it is advantageous to increase the conveying efficiency of the bubble up auger without increasing the speed or diameter of the auger. An increase in auger speed increases grain damage, wear on the auger, and maintenance costs. An increase in auger diameter increases weight and cost.
Thus, there is still a need for a bubble up auger capable of increasing or maximizing its throughput and efficiency. Such a need is satisfied by the bubble up auger of the present invention.